LC-MS/MS comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-03-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
SR9009 is a synthetic small molecule studied as a REV-ERB agonist. REV-ERBα and REV-ERBβ are nuclear receptors that help regulate circadian rhythms and metabolic gene expression. The compound was identified in academic screening efforts to find synthetic ligands for these receptors. In cell and animal studies, SR9009 alters transcription of genes involved in lipid and glucose metabolism, and it can shift circadian behavior. It is not an approved therapeutic agent.
Mechanistically, SR9009 binds the ligand-binding domain of REV-ERBα/β and enhances recruitment of corepressor complexes. This represses target genes rather than activating them. Because REV-ERB proteins normally compete with ROR proteins at shared response elements, the net effect depends on tissue and timing. Researchers use SR9009 to probe how nuclear receptor signaling links the clock to metabolism, inflammation, and muscle biology. Findings are largely preclinical, and the precise contribution of each receptor subtype remains under study.
In rodent studies, SR9009 has been reported to increase mitochondrial content in skeletal muscle and improve exercise endurance under some conditions. These findings led to popular descriptions such as an exercise mimetic, although that term oversimplifies the biology. Effects vary by dose, timing, tissue, and model. The compound's influence on circadian pathways means that time of administration can matter in experiments. Whether similar metabolic changes occur in humans remains largely unexplored in controlled published trials.
Pharmacokinetic data for SR9009 are limited in published literature. Some reports indicate low oral bioavailability and rapid clearance in animals, which complicates interpretation of exposure and effect. Researchers often use injected routes in preclinical work to achieve measurable systemic levels. Analytical studies rely on mass spectrometry to detect the parent compound and its metabolites. Questions about tissue distribution, active metabolites, and long-term consequences remain open. Species differences in metabolism can affect observed half-life and target engagement.
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. These receptors help regulate circadian rhythms and metabolic gene expression. In laboratory experiments, SR9009 binds these receptors and alters transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. It is not a naturally occurring compound and has no approved therapeutic use. Research interest stems from its ability to modify energy metabolism in cells and animal models.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic REV-ERB agonist | Small-molecule ligand; not a hormone or peptide |
| Molecular formula | C20H24ClN3O4S | Reported for the free base |
| CAS Registry Number | 1379686-30-2 | Unique chemical identifier |
| Common synonyms | SR9009; stenabolic | Stenabolic is informal and not an official name |
| Reported targets | REV-ERBα and REV-ERBβ | Nuclear receptors linked to circadian and metabolic regulation |
SR9009 is a synthetic small molecule studied as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is not an approved medicine and has no established human therapeutic use. The compound appears in scientific literature as a tool for probing circadian and metabolic regulation. Online sellers often label it as a research chemical, sometimes using the nickname Stenabolic. Its chemical identity is distinct from selective androgen receptor modulators, stimulants, and peroxisome proliferator-activated receptor delta agonists. Researchers use it mainly in cell and animal experiments.
At the molecular level, SR9009 binds REV-ERBα and REV-ERBβ and alters their repressive activity on target genes. These nuclear receptors help regulate the circadian clock, lipid synthesis, glucose metabolism, and inflammatory pathways. By changing transcription, the compound can shift the timing or magnitude of downstream metabolic processes in model systems. It does not act through androgen receptors or adenosine receptors, which distinguishes it from several substances sold for athletic performance. Whether the same transcriptional changes occur in humans at tolerable exposures remains an open question because controlled human studies are lacking.
Preclinical reports describe effects on exercise endurance, mitochondrial content, and lipid profiles in rodents, but these findings come from specific experimental conditions. Many studies use high doses or delivery methods that may not translate directly to human use. SR9009 has been reported to have low oral bioavailability and a short half-life, which complicates interpretation of oral dosing studies. It is not established as safe or effective for any indication. Literature discussions often separate its pharmacological mechanism from unverified claims made in fitness and supplement markets.
SR9009 binds REV-ERB receptors and alters their repressive activity on target genes. This action can change transcription of genes involved in lipid handling, glucose metabolism, and mitochondrial function. In rodent studies, treated animals have shown changes in muscle oxidative capacity and exercise performance, though effects vary by dose, duration, and model. The precise molecular steps connecting receptor binding to whole-body outcomes are still an active area of investigation. Findings in animals do not automatically translate to humans.
Because REV-ERB receptors are core clock components, SR9009 has been examined for effects on daily rhythms as well as metabolism. Research has explored whether the compound can shift or reinforce circadian gene expression in tissues such as liver and muscle. Some studies report improved metabolic markers in obese or diabetic mice, while others show context-dependent responses. Questions remain about which effects are direct, which are secondary to timing, and how they might differ across species.
SR9009 is a synthetic small molecule studied as an agonist of REV-ERB nuclear receptors. REV-ERB alpha and REV-ERB beta help regulate circadian rhythms and metabolic gene expression. In laboratory research, SR9009 has been used to probe how these receptors affect skeletal muscle, liver, and adipose tissue. The compound was identified in academic drug-discovery work and is often described in scientific literature by its chemical name and research code. It is not an approved medicine, and human clinical data remain limited or absent.
Identity and purity testing for SR9009 commonly uses liquid chromatography coupled with tandem mass spectrometry. This method separates the compound from matrix components and detects it by mass-to-charge transitions, providing sensitive and specific confirmation. Nuclear magnetic resonance spectroscopy can support structural identification, while high-performance liquid chromatography with ultraviolet detection may estimate purity. Because online products labeled as SR9009 may contain other substances or no active compound at all, independent verification is important in research settings. Certificates of analysis are useful but not a substitute for in-house testing.
Laboratory samples of SR9009 are typically supplied as a white to off-white powder. The compound dissolves readily in organic solvents such as dimethyl sulfoxide and ethanol, while its solubility in water is low. Because of this solubility profile, researchers often prepare concentrated stock solutions in an organic solvent before diluting them into aqueous assay buffers. Light exposure, moisture, and repeated freeze-thaw cycles can degrade many small molecules, so handling procedures usually aim to minimize these factors. Purity is commonly checked before use.
Storage conditions for research-grade SR9009 generally involve a freezer at approximately minus twenty degrees Celsius, sometimes lower for long-term preservation. Containers should remain tightly closed and protected from light. Desiccants may be used to limit moisture uptake. Solutions are often stored in aliquots to avoid repeated warming and cooling. Stability data for the compound under various conditions are limited, so laboratories typically follow supplier recommendations and verify performance through periodic analytical checks rather than assuming indefinite stability.
Scientific discussion of SR9009 often separates animal evidence from human anecdote. Rodent studies provide controlled data on endurance, metabolism, and gene expression, but they use specific strains, doses, and treatment durations. Human reports are mostly uncontrolled and cannot establish cause and effect. Open questions include oral bioavailability, tissue distribution, metabolic stability, and long-term effects. Review articles generally call for more rigorous pharmacokinetic and safety research before any clinical use could be considered.
Analytical methods for SR9009 typically rely on liquid chromatography coupled with tandem mass spectrometry. The technique can separate the parent compound from related substances and detect low concentrations in biological matrices. Urine and blood are common samples in anti-doping testing, while in vitro studies may use cell culture media. Rapid metabolism and low expected concentrations make method validation important for reliable identification. Exact metabolite patterns can vary by species and are not fully mapped.
A trackway consisting of four footprints discovered near Marmarth, North Dakota in 2025 and described in 2026 have been attributed to an adult Tyrannosaurus based on the shape and size of the tracks, which measure 1 m (3.3 ft). The set of tracks suggests a stride length of 4 m (13 ft) for the animal that made them, with speed estimates of 1.5–2 meters per second (3.4-4.5 mph). The fluvial environment of the upper Hell Creek Formation, from which the footprints were unearthed may explain the significant scarcity of trackways and the uncommon nature of theropod footprints in the formation in general. Three of the footprints are expected to be recovered in autumn of 2026 to be displayed at the Denver Museum of Nature and Science.
While the review in the JB&JS was able to correlate receiving rodding surgery with greater mobility across all types of OI, in patients with type IV, the surgery did not decrease the incidence of broken bones as compared to non-rodded patients—while type IV patients with rodded tibiae experienced 0.93 tibia fractures per year, patients with natural tibiae experienced only 0.81. However, in patients with type III, rodding surgery decreased the average number of tibia fractures per year from 0.84 to 0.57.
Rubidium was discovered in 1861 by Robert Bunsen and Gustav Kirchhoff, in Heidelberg, Germany, in the mineral lepidolite through flame spectroscopy. Because of the bright red lines in its emission spectrum, they chose a name derived from the Latin word rubidus, meaning "deep red". Rubidium is a minor component in lepidolite. Kirchhoff and Bunsen processed 150 kg of a lepidolite containing only 0.24% rubidium monoxide (Rb2O). Both potassium and rubidium form insoluble salts with chloroplatinic acid, but those salts show a slight difference in solubility in hot water. Therefore, the less soluble rubidium hexachloroplatinate (Rb2PtCl6) could be obtained by fractional crystallization. After reduction of the hexachloroplatinate with hydrogen, the process yielded 0.51 grams of rubidium chloride (RbCl) for further studies. Bunsen and Kirchhoff began their first large-scale isolation of caesium and rubidium compounds with 44,000 litres (12,000 US gal) of mineral water, which yielded 7.3 grams of caesium chloride and 9.2 grams of rubidium chloride. Rubidium was the second element, shortly after caesium, to be discovered by spectroscopy, just one year after the invention of the spectroscope by Bunsen and Kirchhoff. The two scientists used the rubidium chloride to estimate that the atomic weight of the new element was 85.36 (the currently accepted value is 85.47).
On 3 March, US and Israeli strikes destroyed the SNSC headquarters, the Expediency Discernment Council building in Tehran, and what Israeli officials described as an alleged underground nuclear weapons facility called Min Zadai. The proximity of these strikes to the Bushehr Nuclear Power Plant (about 12 km (7.5 mi) away) prompted the Russian agency Rosatom to suspend construction on new units and evacuate non-essential staff. A CIA site in the US embassy in Riyadh was hit by Iranian drones. US officials said its forces had severely damaged Iran's naval capabilities, mainly in the Gulf of Oman, where several Iranian warships were destroyed and key bases hit. Debris from an airstrike damaged Golestan Palace, a UNESCO World Heritage Site, causing UNESCO to issue a statement that damaging UNESCO sites is against international law. Israel Katz authorized a ground invasion of Lebanon on 3 March with forces from the 91st Division, with the stated goal to establish a "security layer" against Hezbollah. The Lebanese government reported that Israeli attacks reached Kfarkela and Qouzah, leading the Lebanese army to redeploy from newly established border posts. Israel reported that it killed Daoud Alizadeh, the commander of the Quds Force's Lebanon branch, in Tehran. Western diplomats said Qatar had struck Iran after Iran had attempted to strike Doha's airport and Qatar shot down two Iranian Su-24 bombers. Qatar denied the accusation that it had joined the "campaign targeting Iran".
Sources: en.wikipedia.org
== Career == Following his postdoctoral fellowship at Harvard University, Lectka joined Johns Hopkins University as an assistant professor of chemistry in 1994. He was promoted to associate professor in 1999 and to professor in 2002. In 2012, he was appointed as the Jean and Norman Scowe Professor of Chemistry at Johns Hopkins University.
==== AP1 ==== Activation of AP1 factor involves three MAPK signaling pathways. These pathways use a phosphorylation cascade of three successive acting protein kinases to transmit a signal. The three MAPK pathways in T cells involve kinases of different specificities belonging to each of the MAP3K, MAP2K, MAPK families. Initial activation is done by the GTPase Ras or Rac which phosphorylate the MAP3K. A cascade involving the enzymes Raf, MEK1, ERK results in the phosphorylation of Jun, conformational change allows Jun to bind to Fos and hence AP-1 to form. AP-1 then acts as transcription factor. Raf is activated via the second messenger DAG, SOS, and Ras. DAG recruits among other proteins the RAS guanyl nucleotide-releasing protein (RasGRP), a guanine nucleotide exchange factor (GEF), to the membrane. RasGRP activates the small GTPase Ras by exchanging guanosine diphosphate (GDP) bound to Ras against guanosine triphosphate (GTP). Ras can also be activated by the guanine nucleotide exchange factor SOS which binds to the LAT signalosome. Ras then initiates the MAPK cascade. The second MAPK cascade with MEKK1, JNKK, JNK induces protein expression of Jun. Another cascade, also involving MEKK1 as MAPK3, but then activating MKK3 /6 and p38 induces Fos transcription. Activation of MEKK1, additionally to being activated by Ras, involves Slp-76 recruiting the GEF Vav to the LAT signalosome, which then activates the GTPase Rac. Rac and Ras activate MEKK1 and thereby initiate the MAPK cascade.
=== Cited texts === Dhillon, Karminder Singh (2009). Malaysian Foreign Policy in the Mahathir Era 1981–2003: Dilemmas of Development. NUS Press. ISBN 978-9971-69-399-2. Milne, R. S.; Mauzy, Diane K. (1999). Malaysian Politics under Mahathir. Routledge. ISBN 0-415-17143-1. Morais, J. Victor (1982). Mahathir: A Profile in Courage. Eastern Universities Press. OCLC 8687329. Sankaran, Ramanathan; Mohd Hamdan Adnan (1988). Malaysia's 1986 General Election: the Urban-Rural Dichotomy. Institute of Southeast Asian Studies. ISBN 981-3035-12-9. Stewart, Ian (2003). The Mahathir Legacy: a Nation Divided, a Region at Risk. Allen & Unwin. ISBN 1-86508-977-X. Wain, Barry (2010). Malaysian Maverick: Mahathir Mohamad in Turbulent Times. Palgrave Macmillan. ISBN 978-0-230-23873-2. James Chin & Joern Dosch. Malaysia Post Mahathir: a decade of change?. Marshall Cavendish. 2016. ISBN 9814677558
Sources: en.wikipedia.org
=== Magnetic bead method === New extraction techniques have been developed using magnetic beads for the purification of nucleic acids by taking advantage of the charged and polymeric nature of long strand of DNA. Beads are both uncoated to increase surface are and yield, while others are more selective by being coated with functional groups that interact with the polymers present in microbes. One common method is to use polyethylene glycol to drive DNA binding to the magnetic beads. The molecular weight and concentration of the PEG will control what molecular weight DNA binds.
Reviews have also found that populations that are believed to be especially high consumers of aspartame, such as children and diabetics, are below the ADI for safe consumption, even considering extreme worst-case scenario calculations of consumption. In a report released on 10 December 2013, the EFSA said that, after an extensive examination of evidence, it ruled out the "potential risk of aspartame causing damage to genes and inducing cancer" and deemed the amount found in diet sodas safe to consume.
The term "concentration camp" was used to describe camps operated by the British in South Africa during this conflict in the years 1900–02, and the term grew in prominence during this period. The camps had originally been set up by the British Army as "refugee camps" to provide refuge for civilian families who had been forced to abandon their homes for whatever reason related to the war. However, when Kitchener took over in late 1900, he introduced new tactics in an attempt to break the guerrilla campaign and the influx of civilians grew dramatically as a result. Disease and starvation killed thousands. Kitchener initiated plans to
The soluble extract alone or the insoluble residues alone were incapable of new bone induction. This work suggested that the optimal osteogenic activity requires a synergy between soluble extract and the insoluble collagenous substratum. It not only represented a significant advance toward the final purification of bone morphogenetic proteins by the Reddi laboratory, but ultimately also enabled the cloning of BMPs by John Wozney and colleagues at Genetics Institute.
Sources: en.wikipedia.org
SR9009 is a synthetic compound investigated as an agonist of the nuclear receptors REV-ERBα and REV-ERBβ. It is used in preclinical research on circadian rhythm and metabolism. It is not an approved drug.
No. It has no approved medical indication, and human safety and efficacy data are limited. It appears in research chemical markets and is banned by some sports authorities.
Natural ligands include heme and certain metabolites; SR9009 is a synthetic small molecule with higher potency and selectivity in some assays. Its effects depend on cell type and timing. It is not a naturally occurring compound.
It is a synthetic research compound that activates REV-ERB nuclear receptors. It is not an approved drug or dietary supplement. Most information comes from cell and animal studies.